1. Field of the Invention
The present invention relates to an interbody cage and, more particularly, to an interbody cage for spine fusion, which is capable of enhancing the growing speed and stability of bones as well as an easy 2D-to-3D conversion in structure.
2. Description of the Related Art
Recently, cases of spinal diseases have occurred often, since the numbers of office workers and elders are increasing, and spinal diseases are common in these two groups. Therefore, how to take care of patients of spinal diseases has become more and more important.
Generally, medical attention of a spinal patient after an operation is extremely important for the patient's recovery, and the patient usually has to put on a spinal brace for a long time so that the spinal brace may provide an external support for the spine of the patient and prevent the recovering spine from injury again.
Nowadays, the way to improve the patient's recovery is to implant an interbody cage in a position adjacent to a bone defect in his spine, with filler such as Calcium Phosphate, bone graft, and auto-genous graft in the interbody cage. However, the filler inside the interbody cage may easily flow away due to intrusion of soft tissues, which usually grow faster than bone tissues, in the interbody cage or circulatory system if the meshes of the interbody cage are not well designed. Thus, this implant made of the interbody cage and filler will not achieve a desirable performance.
Referring to FIG. 1, a conventional interbody cage 9 disclosed by Taiwan Patent No. of M333884 is shown. The interbody cage 9 has a head 91 on the front side thereof, a room 92 formed behind the head 91, a plurality of holes 93 arranged in lateral walls of the interbody cage 9 and communicating with the room 92, a base 94 on the rear side of the interbody cage 9, and a fixing seat 95 for the base 94 to firmly mount on. The room 92 is arranged for insertion of the filler, and the filler inside the interbody cage 9 is accessible to the bone cells of a spine through the holes 93 for spine fusion.
However, there should be a plurality of screws 96 coupling with the fixing seat 95 to firmly position the interbody cage 9 in a position adjacent to a bone defect.Futher, this conventional interbody cage 9 is suitable to be positioned between two vertebral columns only. Moreover, the complexity, difficulty in manufacture and manufacture cost of this conventional interbody cage 9 are high, since the interbody cage 9 can only be shaped by 3D laser carving and spark-discharge forming. Additionally, in a medical operation, this complex interbody cage 9 also leads to a long time period in assembly of the screws 96 and the fixing seat 95. Thus, the possibility of bacterial infection in the medical operation can be largely raised.
Furthermore, the filler loss problem due to soft tissues' intrusion and to the circulatory system may easily occur in this interbody cage 9, since the room 92 and holes 93 are not particularly designed to block the intruded soft tissues and the filler inside the room 92. Accordingly, the conventional interbody cage 9 cannot effectively enhance the growing speed of a defective bone but only serves as a support. Thus, the interbody cage 9 cannot help a lot in recovery of the bone.
Therefore, a titanium-based interbody cage for enhancing the growing speed and stability of defective bones and suitable for use in any part of the spine is needed to solve the above problems.